Australian heatwave set to worsen as fires rage

Firefighters try to contain wildfires in the Stoneville area, a suburb east of Perth in the state of Western Australia on January 12, 2014

Australians sweltering through a severe heatwave were warned on Thursday that the worst Is yet to come, with hundreds of fires raging in several states and temperatures nearing record highs.

Most of southeast Australia has been sizzling in a heatwave that triggered a devastating wildfire on the west coast, razing 55 homes and claiming one life on Sunday.

The mercury has soared above 40 degrees Celsius (104 Fahrenheit) for successive days in South Australia and there is a total ban on recreational fires in neighbouring Victoria where players at the Australian Open fainted and vomited in blistering conditions.

Play was halted on Thursday afternoon due to the extreme heat, and a Melbourne school gardener, aged 76, died after collapsing on Wednesday in the grounds.

Commuters were urged to leave work early to ease peak-hour pressure on trains and trams, with the heat expected to cause significant delays and a wild evening hailstorm forecast.

Health officials in South Australia said 129 people had presented to hospital in the past three days with heat exhaustion and dehydration.

In Victoria state, currently experiencing its longest stretch of hot days since 1908, there were 109 cases and ambulance services reported almost double the average number of call-outs for heart attacks.

Wildfires raged across both states, with South Australia's Country Fire Service saying there were some 800 blazes of concern and an "escalating fire pattern over the next 48 hours", with total fire bans across the state from Friday.

Map showing heatwave forecast for Australia

"We may be reaching quite a dangerous phase in this heat wave and it's important that people are well aware of those risks," said state premier Jay Weatherill.

"Because we appear to be getting closer to some of the cooler weather does not mean that the threat is receding. If anything the threat is increasing."

Acting chief meteorologist for South Australia, John Nairn, said the state capital Adelaide was on track to eclipse its hottest ever temperature of 46.1 Celsius, recorded in January 1939, briefly earning it the title of hottest city on Earth on Thursday.

"We're seeing today as a day where we may well set a record. We have a clear-sky day, the potential is there to reach that 46 degrees in Adelaide," he said.

Cyclists and spectators in Adelaide for next week's Tour Down Under road race were urged to be extra careful venturing into the heat, warnings that were echoed for the large crowds in Melbourne for the Australian Open.

In Victoria, 1,000 fires have been reported in the past 24 hours—mostly due to lightning strikes—and 39 had taken hold, with four declared emergencies.

Friday is expected to bring horrific conditions for fire crews, with strong gusts and a wind change forecast before a cool front arrives.

A wildfire in the Stoneville area, a suburb east of Perth in the state of Western Australia, on January 12, 2014

Officials are warning of some of the worst fire weather in the state since 2009, when the so-called Black Saturday inferno killed 173 people and razed entire towns.

A heatwave ahead of that disaster killed 374 people in Victoria and another 64 in South Australia.

The Climate Council thinktank said new research had showed that heatwaves were becoming longer and more frequent in Australia, with heat records toppling three times as often as cold records and the number of hot days more than doubling.

Tennis fans rest indoors after play was suspended due to 'extreme' heat on day four of the Australian Open tournament, in Melbourne, on January 16, 2014

"Australia has always had hot weather. However, climate change is loading the dice towards more extreme hot weather," said the council's Will Steffen.

"The current heatwave follows on from a year of extreme heat, the hottest summer on record and the hottest year on record."